Overclocking Core i7-3770K: Learning To Live With Compromise

By Achim Roos, Patrick Schmid
published

We recently took our first look at Intel's Ivy Bridge architecture. Then, we evaluated its efficiency. Now, we turn to overclocking. Recently, each of Intel's die shrinks has helped increase frequency headroom. This time, however, we ran into some walls.

Practical Advice: Sandy Or Ivy Bridge?

We've now illustrated that Ivy Bridge dissipates its heat in a much smaller die than Sandy Bridge, and then uses a less effective mechanism for transferring it away from the die and out to a heat spreader. Once the overclocked processor's four cores are saturated, the temperature increase happens so fast that the CPU's thermal monitor triggers throttling faster than we could take and save a screen shot of Core Temp. The jump was phenomenal, taking less than a second from idle to throttling temperature. In the end, we had to use a script to take the shot.

Getting Rid Of Excess Heat

Our experience highlights one of the obstacles that prevents higher clock rates on Ivy Bridge-based CPUs: the cooling subsystem must be able to operate effectively and without any delay. On air, the throttling mechanism triggers before a cooling fan can spin up. We didn't have the luxury of risking the destruction of our test chips by prying their heat spreaders off, and we don't recommend that drastic step to anyone, really. So, we're recommending a closed-loop liquid cooling setup, at least. More extreme enthusiasts can pick a more serious cooling technology, of course.

An X79 platform with water cooling: An Ivy Bridge on the Z77 platform needs it more direly.

Recommendations

We state without any hesitation: air-cooled Ivy Bridge-based processors cannot be overclocked as much as Sandy Bridge-based processors. Overclockers hunting for the latest and greatest overclockable processor, yearning for high-frequency overclocks, should keep that in mind. Maybe a Sandy Bridge-based chip is still the best choice, even in a world where Ivy Bridge exists.

If scalability isn't as big of a worry for you, Ivy Bridge is the more natural choice. Its performance per clock is a few percent higher, so long as you're looking at the same frequency from both architectures. After all, a 4.5 GHz Ivy Bridge-based CPU wins benchmarks against a Sandy Bridge processor at slightly higher clock rates. When you limit your overclock of a chip like the Core i7-3770K to 4.2 or 4.3 GHz, you’re completely on the safe side. There is no temperature issue, and performance remains impressive. Then again, such a system won’t be significantly faster than a machine running at its stock clocks.

Achim Roos
Achim Roos
143 Comments Comment from the forums
  • mayankleoboy1
    Nice review!

    1. Are there plans to release any K CPU's without the HD4000? will they OC higher?

    2. Any chance of intel releasing a second stepping of K-series IB chips?
    Reply
  • mayankleoboy1
    i agree that SB chips spoiled the OC world by making OC so easy and fruitful. IB has nothing to compare it to except SB.
    Reply
  • vilenjan
    Good old Intel. No competition and look what happens, the new generation is barely an upgrade over the previous. Anyone remember Intel PII 450s and the PIII 450s?
    Reply
  • ta152h
    I'm not sure why the reviewers spent so much time figuring out the shrink made the core more dense, and somehow thought this was significant. I mean, really, this happens virtually every shrink, and this time the power dropped more than normal. Common sense should be telling people this is not the cause, but somehow people aren't understanding this.

    It's very interesting that replacing the paste makes so much difference. This is obviously something Intel is aware of, since they do plenty of testing, and obviously chose anyway. Would a few pennies be worth it for a processor that is clearly on the higher end of the scale? Probably not.

    Most likely, they want to keep selling their real high end processors, and it just won't do to have the 3770K beating their 2011 processors, or being very competitive with the successors to that line when they come out. It makes perfect sense. The 3770K is still a great processor, but if you're really looking for the best, it simply will not do. You're forced to buy the more expensive 3960X, and later the even better IB successor to it, which you can bet will have far better paste, and so will overclock significantly better.

    It's genius. A great product for the vast majority, while leaving more expensive products as the best option for that elite that will actually spend $600 to $1000 for a processor.

    Well done, Intel. It's not like AMD has anything to say about it.
    Reply
  • Without the baseline clock for clock comparison (4.5 sandy vs 4.5 ivy), i'm afraid these results are pretty much useless. It's like doing an uncontrolled experiment and passing it off as real science.
    Reply
  • digiex
    as the manufacturing process gets smaller = Smaller die size, supposed to be cooler temperature,

    but, with small die size = small area for heat dissipation,

    ...an irony that needs to be solved.
    Reply
  • slicedtoad
    Recommending a closed loop liquid cooler? really?

    They perform worse than decent air coolers. The lower end ones (think corsair's h60) perform like mid-low range air coolers and cost more. The better ones (h100 or antec's 920) perform on par or worse and with more noise than a similarly priced noctua. If noctuas looks too ugly for you, phantek and several others offer similar performing models.

    The only reason to get closed loop lc is for looks. I admit they do give your build a nice clean look. That doesn't warrant "So, we're recommending a closed-loop liquid cooling setup, at least" though. If you'd changed that to "We're recommending higher end aftermarket coolers for a decent oc", it would've made more sense.

    Anyway, I'm just nit-picking a single line from the article. All in all, it was a good read. It just makes me upset to hear wrong advice.
    Reply
  • _Pez_
    there is no performance advantage over the i7 2600k except for power consumption. I better buy an i7-3930k.
    Reply
  • mesab66
    Absolutely true, digiex.......not far off the animal world parallel - check out the different temperature regulation methods here between large and small animals, particularly how difficult it is to regulate as the size becomes smaller.
    Reply
  • I would like claims that Ivy Bridge procesor is overheating considerably more then Sandy Bridge addressed. And I thin k Intel really should make a better overall product and not cheat us like this.
    Reply